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Chapters 1 thru 5 Database Development Processes

Chapters 1 thru 5 Database Development Processes. Jason C. H. Chen, Ph.D. Professor of MIS School of Business Administration Gonzaga University Spokane, WA 99258 chen@jepson.gonzaga.edu. Figure 1-3: Comparison of enterprise and project level data models. Segment of an Enterprise Data Model.

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Chapters 1 thru 5 Database Development Processes

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  1. Chapters 1 thru 5Database Development Processes Jason C. H. Chen, Ph.D. Professor of MIS School of Business Administration Gonzaga University Spokane, WA 99258 chen@jepson.gonzaga.edu

  2. Figure 1-3: Comparison of enterprise and project level data models Segment of an Enterprise Data Model CUSTOMER ORDER M Q1. One CUSTOMER normally places ___ ORDER? 1 Q2. One ORDER normally is placed by __ CUSTOMER? ORDER PRODUCT M Q3. One ORDER normally places __ PRODUCT? M Q4. One PRODUCT normally is placed by __ ORDER?

  3. Systems Development Life Cycle (SDLC) • Analysis • Feasibility study (capital, technology, organization, legal etc.) • Design • Logical • Physical • Implementation • Coding • Testing • Conversion • Maintenance • H/S W • Firm ware • People ware

  4. Steps in the Database Development Process • Enterprise Modeling • Conceptual Data Modeling • Cuts across Project Initiation and Planning & Analysis phases of SDLC • Logical Database Design (E/R) • Physical Database Design and Creation • Database Implementation • Database Maintenance • Database Growth and Change

  5. The Technology Level of Models • Conceptual models focus on the underlying content of an information system with no assumptions about technology • Logical models assume a general class of technology (H/S W independent) – a relational database and such • Internalmodels assume specific technologies – an Oracle database engine

  6. E/R, OO … Relations Database Meta-data/ Repository/ D.D. Three-schema database architecture External Schema Ch. 1,2 Ch.2, 3,4 Ch. 5 Internal Schema N

  7. Database Schema • External Schema (during the analysis and logical design phases) • User Views • Subsets of Conceptual Schema • Can be determined from business-function/data entity matrices • DBA determines schema for different users • This is part of people-management in databases • Conceptual Schema • ER models (during the analysis phase) • Physical (Internal) Schema • Physical structures (during the physical design phase)

  8. derived/ computed EMPLOYEE multi-valued composite EMPLOYEE e_id e_name e_address (street, city, state, zip) dob date_employed {skill} [years_employed] [age] • Should we create “composite” attributes? (see next slide)? • Should we create “derived/computed” attributes and save physically/ permanently in the database and why? • How to insert values into “multi-valued” attributes?

  9. Logical Model (ERD or E/ERD) Implementation (w/Physical or Internal Model) Steps of Database Development … … User view-1 User view-2 User view-3 User view-N … Conceptual Schema (Model)

  10. Something Missed? Steps of Database Development (MVC) (FIVE figures) … … User view-1 User view-2 User view-3 User view-N … Conceptual Schema (Model) Logical Model (ERD or E/ERD) PHASE I Implementation (w/Physical or InternalModel) PHASE II

  11. Logical Model (ERD or E/ERD) Implementation (w/Physical Model) Steps of Database Development … … User view-1 User view-2 User view-3 User view-N … Conceptual Schema (Model) ???

  12. (Seven) Relations ___________ Logical Model (ERD or E/ERD) _________________ (up to 3NF) __________________ (w/Physical Model) Steps of Database Development … … User view-1 User view-2 User view-3 User view-N … Conceptual Schema (Model) (more relations produced) Transformation (more tables created) NORMALIZATION Implementation

  13. Remove __________ Dependencies Figure: 4-22 Steps in Normalization Table with Multivalued attributes Remove ___________ Attributes Multivalued First normal form (1NF) Partial Remove ___________ Dependencies Second normal form(2NF) Transitive Third normal form (3NF) Remove remaining anomalies resulting from multiple candidate keys Boyce-Codd normal form (BC-NF) Remove Multivalued Dependencies Fourth normal Form (4NF) Remove Remaining Anomalies Fifth normal form (5NF)

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